Control apparatus.



N. W. STORER.

CONTROL APPARATUS.

APPLICATION FILED SEPT- 4. 1913- Patented Apr. 13, 1915.

UNITED STATES PATENT OFFICE.

NORMAN W. STORER, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

CONTROL APPARATUS.

Application filed September 4, 1913.

To all whom it may concern Be it known that I, N ORMAN W. STORER, a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Control Apparatus, of which the following is a specification.

My invention relates to control apparatus, and it hasspecial reference to liquid rheostats which are adapted for use in connection with control systems for electric motors.

The object of my invention is to provide a liquid rheostat of i the above indicated character which shall be simple and durable in construction, efiective in operation, and particularly adapted for use in a system in volving a continuous flow of electrolyte such as is set forth in my Patent 1,056,852, granted Mar. 25, 1913.

Another object of my invention is to provide a liquid rheostat which shall be so constructed as to embody means for reducing the currentto a minimum just prior to the opening of the circuit, in order that the are formed at the instant of interruption shall not be violent and injurious to the apparatus.

In the accompanying drawing, Figure 1 is a view, partially in side elevation and partially in section, of a device constructed in accordance with my invention, and Fig. 2 is a plan view thereof.

Referring to the drawing, the rheostat shown comprises a liquid containing tank 1 having a centrally disposed bottom discharge opening 2, an inlet port 3 located near the bottom, and an overflow port 4 dis posed in the upper portion of said tank. The inlet port is provided with a valve 5 which may be either hand operated or electrically operated for the purpose of controlling the admission of electrolyte into the tank 1, and the discharge opening 2 is similarly provided with a valve 6 for the purpose of opening and closing said discharge ort.

p The tank 1 is substantially rectangular in construction and is preferably made of sheet material, although other types of construction may be employed. Attached to opposite sides of the tank 1 are a plurality of vertically disposed contact plates 7 which project inwardly toward each other in pairs. The tank 1 and the plates 7, just referred to,

Specification of Letters Patent.

Patented Apr. 13, 1915.

Serial No. 788,109.

together constitute one of the electrodes of the rheostat and have an electrical connection 8 to a source of energy (not shown.) A cooperating electrode 9, having an electrical connection 9, is located intermediate the contact plates 7 and comprises a supporting plate 10 and a plurality of vertically disposed contact plates 11 which are secured thereto in pairs and which project outwardly in opposite directions into the spaces between the contact plates 7.

The electrode 9,is secured in position and is insulated from the tank 1 by means of suitable insulating supports 12, and the lower portions of each of the plates 11 are inwardly and downwardly inclined as shown in Fig. 1. A projecting portion or rod 13 of conducting material is secured to, or forms an integral part of, the supporting member 10 of the electrode 9 and is centrally located above the discharge opening 2. A tube or sleeve 11 of insulating mate rial surrounds the projecting portion 13 and is supported in position above the discharge opening 2, preferably by means of a ring 15 and supporting brackets 16, although it may be suitably secured to the electrode itself.

In operation, if the valve 6 in the discharge opening 2 be closed and valve 5 in the inlet port be open to allow the admission of a continuously flowing electrolyte, the tank 1 gradually becomes filled with electrolyte which initially completes a circuit of high resistance between the cooperating electrodes, and which gradually eliminates the resistance from circuit as the tank is filled up to the overflow opening 1.

Assuming that the liquid rheostat is filled with electrolyte and that the discharge opening valve 6 is opened, the electrolyte is allowed to escape. As the level of the electrolyte gradually falls slightly below that of the upper portion of the insulating tube or sleeve 14, the small body of electrolyte con tained within said tube is segregated from the rest of the electrolyte. Hence, a very high resistance is inserted into the circuit just prior to the final interruption thereof. Furthermore, this interruption takes place between the projecting portion 13 of the electrode 9 and the receding electrolyte, so that the arc formed at the instant of break is confined within the non-conducting tube 14 which prevents arcing-over from the portion 13 to the tank 1. The insertion of this high resistance into the circuit at the instant of break cuts the current down to a minimum value and materially reduces the violence of the arc.

Other devices of this general type having structural details which vary materially from those shown, may be constructed without departing from the spirit and scope of my invention and may secure, to a greater or less extent, the benefits and advantages of my invention. I, therefore, desire it to be understood that only such limitations shall be imposed as are indicated in the appended claims.

I claim as my invention:

1. A control apparatus comprising a tank, a body of liquid contained therein, means for permitting the discharge of said liquid therefrom, cooperating electrodes normally immersed in said liquid, and means for restricting the active volume of said liquid at a predetermined point during its discharge whereby the final break is confined to a relatively small body of liquid.

2. In control apparatus, the combination with a tank, a body of liquid contained therein, cooperating electrodes adapted to be immersed in said liquid, and means for discharging said liquid, of means for restricting the active volume of said liquid at a predetermined point during its discharge whereby a high resistance is inserted into circuit prior to the interruption thereof.

3. In a liquid rheostat, the combination with a tank having a discharge opening therein, a body of liquid normally'contained in said tank, and cooperating electrodes suspended therein, of a downwardly projecting portion constituting a part of one of said electrodes, and a sleeve of insulating material surrounding said projecting portion.

4. A liquid rheostat comprising a tank having a bottom discharge opening, a body of liquid contained in said tank, a plurality of vertically disposed plates secured to opposite sides of said tank, an electrode insulated from. said tank and having a' plurality of plates projecting from each side contact plates normally immersed in said.

liquid, one of said electrodeshaving a downwardly projecting lower portion, and atube of insulating material partially surrounding said lower portion and partially projecting into said discharge opening.

In testimony whereof, I have hereunto subscribed my name this 30th day of August, 1913.

NORMAN w. STORER.

Witnesses:

JACOB STAIR, Jr., B. B. Hmns.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G. 

